The invention relates to a chopper for waste material and more particularly for garden waste, comprising a feed hopper and a cutting member arranged at a lower end of the hopper and adapted to be driven for cooperation with a stationary mating knife arrangement.
A chopper of this type has been described in the German patent 3,324,274. In the case of this known arrangement the cutting member is constituted by a knife disk, which is directly mounted on the output shaft of a drive motor and accordingly rotates a very high speed of normally 2,800 rpm. Arrangements of this type have been seen from experience to produce a high noise level. This is due on the one hand to the high speed of rotation of the knife disk. However on the other hand a substantial part of the noise is produced owing to the fact that the material to be chopped is slung against the walls of the hopper. A further particularly significant disadvantage of these arrangements is due to the fact that in this case choppings with a comparatively smooth or intact surface are produced so that there is a comparatively poor mechanical breaking down of the material to be chopped in the sense that organisms causing rotting are not readily able to act on the material. A further point is that known arrangements also necessitate extensive safety precautions to prevent accidents. This applies both for a possible detachment or fracture of the knife disk as well as for the possibility of material being knocked or slung out of the device.